<!doctype html>
<html>
<head>
  <title>Mailgun on Google App Engine Flexible</title>
</head>
<body>
<!-- [START form] -->
<form method="post" action="/send/email">
  <input type="text" name="to" placeholder="Enter recipient email">
  <input type="submit" name="submit" value="Send simple email">
  <input type="submit" name="submit" value="Send complex email">
</form>
<!-- [END form] -->
</body>
</html>
